Old and new stars paint very different pictures of the Triangulum Galaxy

Scientists have discovered something unexpected about the Triangulum galaxy: In this satellite galaxy, a close companion of the much larger Andromeda galaxy, old and new stars occur in separate parts of the its structure, something not seen in galaxies like our own and so far not reporter for other satellite galaxies.

The seven-year photobomb: Distant star’s dimming was likely a ‘dusty’ companion getting in the way, astronomers say

Astronomers discovered that the star Gaia17bpp gradually brightened over a 2 1/2-year period. But follow-up analyses revealed that the star itself wasn’t changing. Instead, it’s likely part of a rare type of binary system. Its apparent brightening was the end of a years-long eclipse by an unusual, “dusty” stellar companion.

Astronomers document the rise and fall of a rarely observed stellar dance

Astronomers have catalogued 126 years of changes to HS Hydra, a rare evolving eclipsing binary. The two stars in HS Hydra began to eclipse each other starting around a century ago, peaking in the 1960s. The degree of eclipsing then plummeted over the course of just a half century, and will cease around Feb. 2021.